Browsing by Author "Cessna, JT"

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    Development of activity standard for 90Y microspheres
    (Elsevier, 2005-08) Mo, L; Avci, B; James, D; Simpson, BRS; van Wyngaardt, WM; Cessna, JT; Baldock, C
    90Y microspheres are important therapeutic radiopharmaceuticals used in the treatment of liver cancer through a process known as selective internal radiation therapy. SIR-spheres® is a radiopharmaceutical product that is comprised of 90Y microspheres suspended in sterile, pyrogen-free water for injection into patients. It is necessary to establish for the SIR-spheres® production the capability of accurately measuring the activity of this product to a traceable national measurement standard. An activity standard for SIR-spheres® was developed from a standard for 90Y solution, employing a highly quantifiable chemical digestion process. Calibration factors for the manufacturer's ionisation chambers were determined for 1 and 5 ml of the SIR-spheres® product placed in Wheaton vials, for both 34% and 44% of 90Y microsphere concentration. © 2005, Elsevier Ltd.
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    Results of an international comparison of activity measurements of 68Ge
    (Elsevier B. V., 2018-04) Cessna, JT; Fitzgerald, R; Zimmerman, BE; Laureano-Pérez, L; Bergeron, DE; van Wyngaardt, WM; Smith, ML; Jackson, TW; Howe, B; da Silva, CJ; Iwahara, A; da Cruz, PAL; Zhang, M; Liu, H; Liang, JC; Fréchou, C; Bobin, C; Cassette, P; Kossert, K; Nähle, O; Marganiec-Gałązka, J; Joseph, L; Ravindra, A; Kulkarni, DN; Yunoki, A; Sato, Y; Lee, KB; Lee, JM; Agusbudiman, A; Dziel, T; Listkowska, A; Tymiński, Z; Sahagia, M; Antohe, A; Ioan, MR; Luca, A; Krivosek, M; Ometakova, J; Javornik, A; Zalesakova, M; García-Toraño Martinez, E; Roteta, M; Mejuto, M; Nedjadi, Y; Juget, F; Yuan, MC; Yeh, CY; Yeltepe, E; Dirican, A; Keightley, JD; Pearce, AK
    An international key comparison, identifier CCRI(II)-K2.Ge-68, has been performed. The National Institute of Standards and Technology (NIST) served as the pilot laboratory, distributing aliquots of a 68Ge/68Ga solution. Results for the activity concentration, CA, of 68Ge at a reference date of 12h00 UTC 14 November 2014 were submitted by 17 laboratories, encompassing many variants of coincidence methods and liquid-scintillation counting methods. The first use of 4π(Cherenkov)β-γ coincidence and anticoincidence methods in an international comparison is reported. One participant reported results by secondary methods only. Two results, both utilizing pure liquid-scintillation methods, were identified as outliers. Evaluation using the Power-Moderated Mean method results in a proposed Comparison Reference Value (CRV) of 621.7(11) kBq g−1, based on 14 results. The degrees of equivalence and their associated uncertainties are evaluated for each participant. Several participants submitted 3.6 mL ampoules to the BIPM to link the comparison to the International Reference System (SIR) which may lead to the evaluation of a Key Comparison Reference Value and associated degrees of equivalence. An international key comparison, identifier CCRI(II)-K2.Ge-68, has been performed. The National Institute of Standards and Technology (NIST) served as the pilot laboratory, distributing aliquots of a 68Ge/68Ga solution. Results for the activity concentration, CA, of 68Ge at a reference date of 12h00 UTC 14 November 2014 were submitted by 17 laboratories, encompassing many variants of coincidence methods and liquid-scintillation counting methods. The first use of 4π(Cherenkov)β-γ coincidence and anticoincidence methods in an international comparison is reported. One participant reported results by secondary methods only. Two results, both utilizing pure liquid-scintillation methods, were identified as outliers. Evaluation using the Power-Moderated Mean method results in a proposed Comparison Reference Value (CRV) of 621.7(11) kBq g−1, based on 14 results. The degrees of equivalence and their associated uncertainties are evaluated for each participant. Several participants submitted 3.6 mL ampoules to the BIPM to link the comparison to the International Reference System (SIR) which may lead to the evaluation of a Key Comparison Reference Value and associated degrees of equivalence. An international key comparison, identifier CCRI(II)-K2.Ge-68, has been performed. The National Institute of Standards and Technology (NIST) served as the pilot laboratory, distributing aliquots of a 68Ge/68Ga solution. Results for the activity concentration, CA, of 68Ge at a reference date of 12h00 UTC 14 November 2014 were submitted by 17 laboratories, encompassing many variants of coincidence methods and liquid-scintillation counting methods. The first use of 4π(Cherenkov)β-γ coincidence and anticoincidence methods in an international comparison is reported. One participant reported results by secondary methods only. Two results, both utilizing pure liquid-scintillation methods, were identified as outliers. Evaluation using the Power-Moderated Mean method results in a proposed Comparison Reference Value (CRV) of 621.7(11) kBq g−1, based on 14 results. The degrees of equivalence and their associated uncertainties are evaluated for each participant. Several participants submitted 3.6 mL ampoules to the BIPM to link the comparison to the International Reference System (SIR) which may lead to the evaluation of a Key Comparison Reference Value and associated degrees of equivalence. © 2021 Elsevier Ltd.